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How much power can these LEDs handle? Answered

I'm working on a project and I would like to connect two green LEDs two ultra bright Red LEDs and 2 blue LEDs. I got the green leds from radio shack so i know they need 2.1v dc, 25ma but the red ones and blue ones I got from some old toys so I don't know what they need. Any Ideas how much power I would need if I connected them in series? I have a bunch of old wall warts of varying sizes (9v 350ma, 9v 210ma, 5v 1a, 12v 750ma 12v 150ma) but only a few LEDs so I don't want to fry them and I don't need to push them to the limts. Here's some pics of my LEDs the small one is the blue one and the other clear one is Red.



10 years ago

10 mA is safe for all leds blue leds often give a lot of light on very low current power up on 10 mA and see. if you overpower a led (but not too much) itll heat up and get quite hot before damage is done. if it heats too much after few minutes use larger resistor. if its cool you may try lower resistor